Hose

ABSTRACT

The present invention relates to a medium-carrying hose, preferably for pressure medium and for use in, for instance, an engine unit, the wall of the hose comprising at least one wall portion ( 5 ). The wall portion ( 5 ) is connected with at least one expansion portion ( 4 ) to form a continuous hose casing, so that the circumference of the hose is variable between a minimum value, when the expansion portion ( 4 ) is unexpanded, and a maximum value, when the expansion portion ( 4 ) is maximally expanded. The expansion portion ( 4 ) extends in the transverse and the longitudinal direction of the hose, the wall portions ( 5 ) being displaced relative to each other both in the transverse and in the longitudinal direction of the hose as the circumference increases and the expansion portion ( 4 ) expands. The invention also relates to a method for manufacturing such a hose.

This application is the national phase under 35 U.S.C. §371 of PCTInternational Application No. PCT/SE00/01163 which has an Internationalfiling date of Jun. 6, 2000, which designated the United States ofAmerica and was published in English.

FIELD OF THE INVENTION

The present invention relates to a medium-carrying hose, preferably forpressure medium and for use in e.g. engine compartments, the wall of thehose comprising at least one wall portion which is connected with atleast one expansion portion to form a continuous hose casing. Thecircumference of the hose is variable between a minimum value, when theexpansion portion is unexpanded, and a maximum value, when the expansionportion is maximally expanded.

The invention also relates to a method for manufacturing such a hose.

BACKGROUND ART

Hoses of the type that is used in engine compartments are subjected tovarious effects of the surroundings. For instance, they can be subjectedto pressure, from inside or from outside, or to relatively powerfulvibrations as the engine is running. The space for hoses in motorcompartments and the like is usually very limited. For an engine unit tobe compact in terms of space, it is often necessary that the hoses bepreformed and bent in given directions to fit between the othercomponents of the engine. However there is one problem since the hose,when pressurised, tends to move or bulge in the engine compartment. Thehose may then abut against other parts of the engine body, which forinstance because of their temperature may damage the hose. Thissituation may also arise if the hose vibrates in the operation of theengine. Both pressurising and vibration besides cause a strain to theattachment of the hose in the engine unit.

There are today a plurality of hoses which have some kind of bellowsstructure at their ends, thereby reducing the vibrations in theattachment of the hose. However, such bellow structures do not affectthe motion of the various parts of the hose, which are still essentiallyfree and can abut against neighbouring objects.

Such a hose is disclosed in e.g. EP 0 791 775, where flexible portionsat the ends of the hose are combined with a rigid hose portion in themiddle of the hose. Vibrations are absorbed in the longitudinaldirection of the hose at the hose ends, but otherwise the hose isallowed to move freely.

SUMMARY OF THE INVENTION

According to the invention the above problems are solved by a hose ofthe type mentioned by way of introduction, the expansion portion of thetube extending in the transverse and the longitudinal direction of thehose, the wall portions being displaced relative to each other in thetransverse as well as the longitudinal direction of the hose as thecircumference increases and the expansion portion expands.

By the expansion portion extending in the transverse and thelongitudinal direction of the hose, the wall portions will be displacedin the transverse as well as the longitudinal direction when, forinstance, pressurizing the hose. The direction of motion of the portionsduring pressurising can thus be controlled, so that there is no risk ofthe hose touching other components in, for example, an engine unit. Thewall portion has a substantially constant diameter and the expansionportions have a substantially smaller diameter than the wall. Theexpansion portion can extend first in one then in other direction, ordiagonally across the transverse and the longitudinal direction of thehose. Also vibrations will be efficiently damped in a desirable mannerwhen the vibrating motion of the wall portion is absorbed by theexpansion portion. This means that the wall portion, and thus the hose,can be controlled in a desirable manner also in case of vibrations.

The wall and expansion portions may, if desirable, be differently formedin different parts along the hose in order to control, during expansionor vibration of the hose, the direction of motion of the different partsin a desirable manner. The relationships of the wall and expansionportions can also differ in different parts along the hose.

In such a hose, which is preformed to have a certain extent in thelongitudinal direction, as is often the case of hoses intended forengine compartments, the design of, and the relationships of, the walland expansion portions in the hose casing in each part of the hose ispreferably adapted to the preform of the hose in the respective parts.One and the same preformed hose can thus advantageously be provided withdifferently formed expansion and wall portions.

Preferably the expansion portion may consist of a groove in the hosecasing when this is in an unexpanded state. Such a groove is relativelyeasy to form by means of a design in which the expansion portion isformed in unity with the wall portion. The expansion of the groove canbesides be controlled with the aid of the shape of its cross-section.

Preferably the groove is helically turned seen in the longitudinaldirection of the hose. The helical shape means directly that theexpansion portion is oriented both in the transverse and in thelongitudinal direction of the hose. Pressure and shocks in bothdirections are therefore efficiently absorbed by the hose.

The number of turns of the helical groove per unit of length of the hosemay be varied to control the hose as desired. The groove may also havedifferent direction of turning in different parts of the hose, ordifferent cross-sectional shape in different parts of the hose. Thisresults in many possibilities of variation.

Preferably the hose has one or more expansion portions, which aredistributed along the circumference of the hose casing, for satisfactorydistribution of the pressure and/or shock equalisation in eachindividual case.

The invention also relates to a method for manufacturing a hose,according to the invention, in which the hose material is extruded. Inaddition to the hose material and together with this, a form material isextruded which is adapted to be a preform for the hose material for thedesired configuration of expansion portions and wall portions. Thispreform serves to facilitate the process of extrusion. When the hosematerial, before blowing, has a relatively small diameter, there is agreat risk that parts of the hose adhere to each other. This concerns inparticular the expansion portions whose dimensions in the non-blownstate are relatively small. A supporting form with expansion and wallportions is formed of the form material during extrusion and preventsproblems in the forming of the hose material.

The form material is suitably arranged along the outer circumference ofthe hose material, which gives practical advantages in the method.

Preferably the form material is accumulated in the portions of the hosematerial which are intended to form expansion portions. These portionsusually constitute formed portions such as grooves. The bulging shapewhich is necessary for the hose is produced by means of an elevatedportion in the form material, thus a thicker portion of form material.

The form material can advantageously consist of an elastic materialwhich extends along the circumference of the hose material. The formmaterial of the completed hose will then be arranged along thecircumference of the hose material and provides a smooth outer face forthe hose. The elasticity of the material serves to make it possible forthe expansion portions still to assume an unexpanded and an expandedstate. A smooth outer face round the hose is advantageous since it iseasier to keep clean than a hose with exposed expansion portions. Thehose is then along its circumference provided with an elastic material.

Further scope of the applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein.

FIG. 1 shows an embodiment of a hose according to the invention.

FIG. 2 is a cross-sectional view along line II—II of the hose in FIG. 1.

FIG. 3 is a cross-sectional view along line III—III of the hose in FIG.1.

FIG. 4 shows a second embodiment of a hose according to the invention.

FIG. 5 is a cross-sectional view along line V—V of the hose in FIG. 4.

FIG. 6 is a cross-sectional view along line VI—VI of the hose in FIG. 4.

FIG. 7 shows a third embodiment of a hose according to the invention.

FIG. 8 is a cross-sectional view along line VII—VII of the hose in FIG.7.

FIG. 9 is a cross-sectional view of one more embodiment of a hoseaccording to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 illustrates a preferred embodiment of a hose according to theinvention. The hose is preformed with a plurality of bends 1, 2 and astraight central portion 3. The circumferential surface of the hose isformed with grooves 4 which extend along the hose. In the first bentpart 1 of the hose, the grooves 4 are helically turned along the hose.In this portion 1, shocks as well as pressure can be absorbed in severaldirections. In the second straight portion 3 of the hose, the number ofturns of the helix per unit of length is considerably smaller, i.e. sosmall that the groove 4 extends essentially along the hose. In themiddle of the straight portion 3, the helical groove 4 changes directionround the hose in order to form in this new direction a helix having alarger number of turns per unit of length in the last, bent part 2 ofthe hose.

The cross-section of the hose is shown in FIG. 2. Here thecross-sectional shape of the grooves 4 is essentially rectangular. Fourgrooves 4 are uniformly distributed along the circumference of the hosewith wall portions 5 therebetween. In one of the end portions of thehose, the hose is smooth and without grooves 4, as shown in FIG. 3.

FIG. 4 shows another embodiment of a hose according to the invention.The helical shape of the grooves 4 is similar to that of the hose inFIG. 1. The cross-sectional shape of the grooves 4, however, isdifferent, which is evident from FIG. 5. Here the grooves 4 form a moreacute angle to the wall portions 5 and between the walls of the groove.This design can, if it is made of the same material as in the embodimentin FIG. 1, absorb greater pressure and more powerful vibrations than inthe embodiment in FIG. 1 owing to the greater expansibility of thegrooves.

FIGS. 7-8 show a hose according to the invention, which is provided withan elastic form material along its circumference. In the manufacture ofthe hose by extrusion, the form material serves to give the hose thedesired form with expansion and wall portions. In this embodiment anelastic form material is used, which is fixedly arranged on the hose andprovides a smooth surface. The smooth surface can be advantageous toprotect the hose from dirt. The elastic material, however, does notsignificantly prevent the relative movability between the portions. Itis also possible to use a form material which is washed away after thehose is completed. Such a form material would then be used only in theextrusion and then be removed from the hose. The final result will thenbe a hose according to, for example, FIGS. 1-3.

It is also possible to arrange an elastic material along the innercircumference of the hose. This yields the same advantages in terms ofmanufacture as those mentioned above, and also gives the hose a smoothinside, which may be advantageous for the flow through the hose. Thecross-section of such an embodiment of a hose according to the inventionis shown in FIG. 9.

It goes without saying that many embodiments in addition to thosedescribed above are feasible. The shapes of the hoses and the grooves 4can be varied in many ways. For example, the cross-sectional shape ofthe groove can be different in different parts of the hose 100. Insteadof having grooves, the expansion portions can be designed in some otherfashion, provided that efficient expansibility is obtained, Forinstance, the expansion portions 4 can be made of an elastic materialwhich is put together with the wall portions 5, or of a weakened areawhich owing to its thinner wall thickness will be more elastic than thesurrounding wall portions 5. By varying the above different parameters,the hose portions can thus be made to be displaced in the desireddirection in pressurising or in case of vibrations. Of course, thepreform of the hose can also be of a different design, according to theinvention, thanks to the expansion portions, can be made flexible. Alsothe direction of the flexibility is then dependent on the relationshipof the expansion portions 4 and the wall portions 5.

Hoses according to the invention may also be provided with certain partswithout any vibration-absorbing arrangements whatever.

Although the embodiments described above constitute hoses with a groovehaving a varying direction of turning in different parts of the hose, itis possible to have the same direction of turning along the entire hose.The cross-sectional shape may also be varied or constant along the hose,according to the requirements in the individual case. The hose can haveone or more expansion portions, which can be uniformly or irregularlyarranged.

It is also possible to have hoses where an elastic material is arrangedboth on the outer and on the inner circumference of the hose. Thearrangement of elastic material can be optimised for manufacture of thehose, for the flow therethrough as well as for cleaning. The effect ofthe grooves on the flow through the hose can optionally be used tocontrol the flow.

The invention being described, it will be obvious that the same may bevaried in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedwithin the scope of the following claims.

What is claimed is:
 1. A medium-carrying hose, a wall of the hosecomprising at least one wall portion which is connected with at leastone expansion portion to form a continuous hose casing, so that thecircumference of the hose is variable between a minimum value, when theexpansion portion is unexpanded, and a maximum value, when the expansionportion is maximally expanded and said expanded portion extends in thetransverse and the longitudinal direction of the hose, the wall portionsbeing displaced relative to each other in transverse as well as thelongitudinal direction of the hose as the circumference increases andthe expansion portion expands, the wall portion has a substantiallyconstant diameter and the expansion portions have a substantiallysmaller diameter than the wall and the wall and expansion portions aredifferently formed in different parts along the hose in order tocontrol, during expansion or vibration of the hose, the direction ofmotion of different parts.
 2. The medium-carrying hose according toclaim 1, wherein relationships of the wall and expansion portions aredifferent in different parts along the hose in order to control, duringexpansion of the hose, the direction of the motion of the differentparts.
 3. The medium-carrying hose according to claim 1 or 2, the hoseis preformed to have a certain extent in the longitudinal direction, andthat the design of, and the relationships of, the wall and expansionportions in the hose casing in each part of the hose is adapted to thepreform of the hose in the respective parts of the hose.
 4. Themedium-carrying hose according to claim 1, wherein the expansion portionis a groove in the hose casing when this is in an unexpanded state. 5.The medium-carrying hose according to claim 4, wherein the groove ishelically turned in the longitudinal direction of the hose.
 6. Themedium-carrying hose according to claim 5, wherein the helical groovehas a varying number of turns per unit of length of the hose.
 7. Themedium-carrying hose according to claim 5 or 6, wherein the helicalgroove has different direction of turning in different parts of thehose.
 8. The medium-carrying hose according to claim 5, wherein thecross-sectional shape of the groove is different in different parts ofthe hose.
 9. The medium-carrying hose according to claim 1, wherein thehose has at least two expansion portions, which are uniformlydistributed along the circumference of the hose casing.
 10. Themedium-carrying hose according to claim 1, wherein the hose has fourwall portions in addition to four expansion portions, which arealternatingly arranged along the circumference of the hose casing.
 11. Amedium-carrying hose, a wall of the hose comprising at least one wallportion which is connected with at least one expansion portion to form acontinuous hose casing, so that the circumference of the hose isvariable between a minimum value, when the expansion portion isunexpanded, and a maximum value, when the expansion portion is maximallyexpanded and said expanded portion extends in the transverse and thelongitudinal direction of the hose, the wall portions being displacedrelative to each other in the transverse as well as the longitudinaldirection of the hose as the circumference increases and the expansionportion expands, the wall and expansion portions are differently formedin different parts along the hose in order to control, during expansionor vibration of the hose, the direction of motion of the differentparts, the hose along its circumference is provided with an elasticmaterial.
 12. A medium-carrying hose, a wall of the hose comprising atleast one wall portion which is connected with at least one expansionportion to form a continuous hose casing so that the circumference ofthe hose is variable between a minimum value, when the expansion portionis unexpanded, and a maximum value, when the expansion portion ismaximally expanded and said expanded portion extends in the transverseand the longitudinal direction of the hose, the wall portions beingdisplaced relative to each other in the transverse as well as thelongitudinal direction of the hose as the circumference increases andthe expansion portion expands, the wall and expansion portions aredifferently formed in different parts along the hose in order tocontrol, during the expansion or vibration of the hose, the direction ofmotion of the different parts, the hose along its inner circumference isprovided with an elastic material.
 13. A method for manufacturing amedium-carrying hose, a wall of the hose comprising at least one wallportion which is connected with at least one expansion portion to form acontinuous hose casing, so that the circumference of the hose isvariable between a minimum value, when the expansion portion isunexpanded, and a maximum value, when the expansion portion is maximallyexpanded and said expanded portion extends in the transverse and thelongitudinal direction of the hose, the wall portions being displacedrelative to each other in the transverse as well as the longitudinaldirection of the hose as the circumference increases and the expansionportion expands, the wall and expansion portions are differently formedin different parts along the hose in order to control, during expansionor vibration of the hose, the direction of the motion of the differentparts by extruding the materials forming the hose, in addition to thehose material and together therewith, a form material, which is adaptedto be a preform for the desired configuration of the expansion portionsand wall portions of the hose material, the form material or beingarranged along one of an outer circumference of the hose material orbeing arranged extending along an inner circumference of the hosematerial.
 14. The method according to claim 13, wherein the formmaterial is arranged along the outer circumference of the hose material.15. The method according to claim 13 or 14, wherein the form material isaccumulated in the portions of the hose material which are adapted toform expansion portions.
 16. The method according to claim 13, whereinthe form material is an elastic material, which extends along thecircumference of the hose material.
 17. The method according to claim16, wherein the form material in the completed hose is arranged alongthe circumference of the hose material and provides a smooth outer facefor the hose.
 18. The method according to claim 13, wherein the formmaterial is removed from the hose material in order to form thecompleted hose.
 19. The method according to claim 18, wherein the formmaterial is washable away from the hose material.
 20. Themedium-carrying hose according to claim 1, wherein the hose is forpressure medium and can be used in engine compartments.
 21. Themedium-carrying hose according to claim 11, wherein the hose is forpressure medium and can be used in engine compartments.
 22. Themedium-carrying hose according to claim 12, wherein the hose is for apressure medium and can be used in engine compartments.
 23. The methodaccording to claim 13, wherein the hose is usable for a pressure mediumand in engine compartments.